Vehicles that are powered by fuel cells, batteries, and hybrid systems that include electric motors are becoming increasingly common in the automotive market. The electric motors are typically controlled using various motor control schemes. One particular type of motor control scheme that is used relies on position and speed feedback, and in some instances temperature feedback, from suitable feedback sensors in the motor to control power electronic devices. The power electronic devices, such as integrated gate bipolar transistors (IGBTs), controllably synthesize a direct current (DC) voltage into an alternating (AC) voltage that is supplied to the electric motor.
An undesirable byproduct of the above-described control scheme action is the potential for generating significant amounts of electromagnetic interference (EMI). This is due, at least in part, to the relatively rapid on-off operations implemented by the power electronics. The cables associated with the feedback sensors, because of their locations within the electric motor, can also be a significant source of EMI. Unfortunately, shielding these cables can exacerbate EMI propagation and/or reduce the shielding effectiveness of the motor cables. Although strategically placed filtering devices, such as inductors, capacitors, and shielded components, can reduce EMI, these components can increase overall system weight, cost, and size.
Accordingly, it is desirable to provide a system and method of reducing EMI emissions in an electric motor control system that does not significantly increase overall system weight, cost, and size. Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background.